The inter-ELM tungsten erosion profile in DIII-D H-mode discharges and benchmarking with ERO+OEDGE modeling

Nuclear Fushion

article

T. Abrams¹  R. Ding²  H.Y. Guo¹  D.M. Thomas¹  C.P. Chrobak³  D.L. Rudakov³  A.G. McLean⁴  E.A. Unterberg⁵  A.R. Briesemeister⁵  P.C. Stangeby⁶  J.D. Elder⁶  W.R. Wampler⁷  J.G. Watkins⁷ 

[1] General Atomics;Oak Ridge Associated Universities;University of California San Diego;Lawrence Livermore National Laboratory;Oak Ridge National Laboratory;University of Toronto Institute for Aerospace Studies;Sandia National Laboratories

关键词: DIII-D;    DiMES;    tungsten;    erosion;    sputtering;    ERO modeling;   

DOI  :  10.1088/1741-4326/aa66b2

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

It is important to develop a predictive capability for the tungsten source rate near the strike points during H-mode operation in ITER and beyond. H-mode deuterium plasma exposures were performed on W-coated graphite and molybdenum substrates in the DIII-D divertor using DiMES. The W-I 400.9 nm spectral line was monitored by fast filtered diagnostics cross calibrated via a high-resolution spectrometer to resolve inter-ELM W erosion. The effective ionization/photon (S/XB) was calibrated using a unique method developed on DIII-D based on surface analysis. Inferred S/XB values agree with an existing empirical scaling at low electron density ( n _e) but diverge at higher densities, consistent with recent ADAS atomic physics modeling results. Edge modeling of the inter-ELM phase is conducted via OEDGE utilizing the new capability for charge-state resolved carbon impurity fluxes. ERO modeling is performed with the calculated main ion and impurity plasma background from OEDGE. ERO results demonstrate the importance a mixed-material surface model in the interpretation of W sourcing measurements. It is demonstrated that measured inter-ELM W erosion rates can be well explained by C→W sputtering only if a realistic mixed material model is incorporated.

【 授权许可】

Unknown